At present, implantable medical devices are typically made of metal and alloys, ceramics, polymers and related composites thereof wherein metal material-based implantable medical devices are especially favored for their superior mechanical properties, such as high strength and high toughness.
Iron, as an important element in the human body, is involved in many biochemical processes, such as oxygen transportation. Easily-corroded pure iron stents, such as Peuster M which were made by laser engraving methods and similar to the clinically used metal stents in shapes were implanted into the descending aorta of 16 New Zealand rabbits. The results of this animal experiment show that there is no thrombosis within 6-18 months, nor adverse events, and it is confirmed from pathological examination that there was no inflammatory response to the local vascular wall, no significant proliferation of smooth muscle cells, which primarily indicates that the degradable iron stents are safe and reliable, and have good application prospects. However, the study found that the pure iron in the body corroded at a low rate, and could not meet the clinical requirement of time for degradation of the degradable stems. Thus, there is a need to improve the corrosion rate of the iron.